The objective of this contract will be to operate the Field Station already established in Iowa in support of the next five years of the Agricultural Health Study. The Field Station will be primarily responsible for updating exposure data on the cohort previously established through administration of a questionnaire, linking the cohort cohort members to vital status and disease registries in the state, coordinating all activities with the Coordinating Center, obtaining buccal swabs on a large fraction of the cohort for processing at the Coordinating Center, coordinating the activities of the U.S. EPA environmental assessment teams with a selected sample of farmers in the study, and related activities as described in the Statement of Work. This study is being issued by the Occupational Epidemiology Branch (OEB), Epidemiology & Biostatistics Program (EPB), Division of Cancer Epidemiology and Genetics (DCEG), National Cancer Institute (NCI) to continue to obtain data to explain why farmers experience an excess of several cancers.